Message man as part of the biosphere. Man as an inhabitant of the biosphere and his influence on the nature of the earth. The relationship "man-biosphere" as a global problem

The biosphere includes:

- living matter - the totality of all living organisms;

-biogenic substance - organomineral or organic products created by living matter;

- bio-inert substance- a substance created by living organisms together with inanimate (inert) nature.

Biosphere- the shell of the Earth, inhabited by living organisms and transformed by them. The biosphere began to form about four billion years ago, when the first organisms began to emerge on our planet. It is in a state of constant disequilibrium, it is a huge machine that uses the energy of the sun's rays for its work. It is constantly evolving, so, two and a half million years ago, the first people appeared, they were hunters and gatherers. Man is often called the peak of the evolution of the living, but the evolutionary relations of the living cannot be depicted as a straight line from the less perfect to the more perfect. Therefore, evolution cannot have one vertex. Man is not the only one who uses tools, some birds and mammals also use them, but man does it as efficiently and perfectly as possible. Man is characterized by consciousness - a perfect form of reflection of the surrounding world, developing, a person improves, speech, writing, learning activities, information exchange appear - this has led to a change in the environment. Human weapons were constantly improved, he exterminated many ungulates and mammoths, which served as the basis of the diet of that time. An alternative was found about ten thousand years ago - humanity moved from hunting and gathering to farming and cattle breeding, although hunting and gathering remained important sources of food. This was the first ecological crisis that arose as a result of human activity in the extermination of large animals.

With the help of production tools, mankind creates an artificial habitat - settlements, dwellings, clothing, food, various machines and accessories (Fig. 2).

Rice. 2. Artificial human habitat ()

The evolution of the biosphere has entered a new phase, where human activity has become a serious force. IN AND. Vernadsky said about this: “Man has never had such an influence on the nature around him as now, never has this influence been so diverse and so strong. The man of the present time is a geological force ... ".

With the advent of agriculture, cattle breeding, mining, the development of agriculture, man began to change the cycle of substances in nature. The use of various fertilizers in agriculture, oil, gas, coal as energy carriers, and mining lead to the depletion of non-renewable natural resources.

With the onset of the Industrial Revolution at the end of the 16th century and the shift from manual labor to machine labor, the scale of human activity increased. The pressure on the environment has increased with the advent of modern industry, the proportion of the urban population and the number of people on the planet have increased (Fig. 3).

Rice. 3. The development of mankind and its infrastructure ()

In order to feed the growing number of people, additional areas were needed for agriculture, for the productivity of which new scientific knowledge was needed. The scientific and technological revolution improved the situation - it became possible to improve the efficiency of agriculture and environmentally friendly production. But with the development of progress, substances alien to living nature also appeared - xenobiotics. These substances and materials fundamentally do not enter the biological cycle of substances, none of the living beings can decompose the waste of many types of plastic, pesticides and ingredients that are used in detergents (Fig. 4).

Rice. 4. Xenobiotics ()

The growth of the population on the planet leads to an increase in the intensity of their activities, which in turn pollutes the environment, leads to a change in its physical and chemical properties, which adversely affects organisms and leads to the loss of irreplaceable natural resources. As a result, there is a problem of a lack of mineral resources and an energy crisis due to the depletion of world oil and gas reserves. In order to preserve irreplaceable resources, methods of their extraction are being improved, all the elements contained in them are more fully extracted from ores, alternative sources - wind, solar, tidal energy - are more widely used to solve the energy problem.

The diversity of living organisms is the basis for the existence of the biosphere. Therefore, by preserving all modern species of organisms, man provides conditions suitable for life on Earth. In recent decades, there has been an active search for the best ways to conduct economic activities in order to cause minimal damage to nature.

According to V.I. Vernadsky, the biosphere will be transformed by man into a noosphere, a sphere reasonably controlled by man. The noosphere is the highest stage in the development of the biosphere, associated with the emergence and formation of a civilized society in it, with a period when intelligent human activity becomes the main factor in development on Earth. Vernadsky wrote: “Humanity, taken as a whole, becomes a powerful geological force. And before him, before his thought and work, the question of the restructuring of the biosphere in the interests of free-thinking humanity as a whole is raised. This new state of the biosphere, to which we are approaching without noticing it, is the noosphere.”

The biosphere existed even before the appearance of man, it can exist without him, so it is worth thinking about how to conduct your activities so as not to harm the environment, because without the biosphere a person cannot exist, he is its natural component. A person is subject to the action of environmental laws, like all living beings on the planet, and is subject to the action of certain environmental factors. Therefore, thoughtless intervention in the biosphere is of an ecosystem nature, each extinct plant species takes with it at least five species of invertebrates, the existence of which is associated with this species. Any living creature on our planet modifies our environment in which natural processes take place, but the role of man in this process is not very clear.

The relationship of a person with the outside world is one of the most difficult issues of bioethics, which requires careful study and wide discussion among scientists and the public of the consequences of man-made environmental changes, solving the problem of waste disposal, biological wastewater treatment, taking into account the patterns that exist in the biosphere. Substances extracted from nature for human needs must be returned to the biosphere in a form suitable for inclusion in the biological cycle, that is, industry must be integrated into the natural circulation of substances in the biosphere.

We discussed with you the bioethical problem of interaction between man and the biosphere, found out that the preservation of environmental patterns is one of the conditions for the survival, preservation and development of human society.

Bibliography

1. Mamontov S.G., Zakharov V.B., Agafonova I.B., Sonin N.I. Biology. General patterns. - Bustard, 2009.
2. Ponomareva I.N., Kornilova O.A., Chernova N.M. Fundamentals of General Biology. Grade 9: A textbook for students in grade 9 educational institutions / Ed. prof. I.N. Ponomareva. - 2nd ed., revised. - M.: Ventana-Graf, 2005.
3. Pasechnik V.V., Kamensky A.A., Kriksunov E.A. Biology. An Introduction to General Biology and Ecology: A 9th Grade Textbook, 3rd ed., stereotype. - M.: Bustard, 2002.

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Homework

1. What does the biosphere include?
2. How does the cycle of substances in nature change with the advent of modern industry?
3. What measures should be taken to conserve irreplaceable resources?

Biosphere- part of the Earth's shell inhabited by living organisms. Includes upper lithosphere, hydrosphere, troposphere, and lower stratosphere. The doctrine of the biosphere was developed by Acad. V. I. Vernadsky.

Noosphere(from Latin "noo" - mind, "reasonable shell" of the Earth) - part of the biosphere, in which human activity is manifested, both positive and negative.

Biomass of the Earth- the totality of all living organisms (living matter) of the planet. Expressed in units of mass or energy per unit area or volume. The biomass of the Earth is 2.423 1012 tons, of which 97% are plants, 3% are animals.

Surface biomass land - the totality of all living organisms - plants, animals, microorganisms that inhabit the land.

Soil biomass-collection living organisms that live in the soil and play a leading role in the process of soil formation. Soil organisms include the most important chemical compounds in the cycle of substances in the biosphere.

Humus(from Latin "humus" - humus) - organic matter of the soil, formed due to the decomposition of plant and animal residues and their metabolic products. The amount of humus serves as an indicator of soil fertility, since it contains all the main plant nutrients (the humus horizon of chernozem soils contains up to 30% humus).

Biomass of the oceans.- the totality of all living organisms that inhabit the main part of the Earth's hydrosphere. Its biomass is 1000 times less than the land biomass. since the use of solar energy in water is 0.04%, on land - 0<1-0,3%.

Biological productivity-quantity organic matter Produced over a certain time by organisms that are part of a particular biogeocenosis (meadows, forests, fields, reservoirs). It is measured in units of mass, time and area.

living matter - the totality of living organisms (biomass) of the biosphere. It is an open system, which is characterized by growth. reproduction, distribution, exchange of substances and energy with the external environment.

Functions of living matter: a) gas - constant gas exchange with the environment in the process of respiration of plants and animals and plant photosynthesis; b) concentration-biogenic migration of atoms, which are first concentrated in living organisms, and then, after their death and mineralization, pass into inanimate nature; c) redox - exchange of matter and energy with the external environment: during dissimilation, organic substances are oxidized, thermal energy is released and the energy of chemical bonds is accumulated in ATP, during assimilation, chemicals necessary for the body are formed due to the assimilation and conversion of nutrients in animals photosynthesis in green plants, using the energy of ATP.

Biochemistry - a science that studies the chemical composition of organisms and the chemical transformations of substances and energy that form the basis of the vital activity of organisms.

Geochemistry- a science that studies the chemical composition of the Earth, the chemical elements in it and their stable isotopes, the patterns of distribution of chemical elements in various geospheres, the laws of their behavior, combination and migration (concentration and scattering) in natural processes.

Biogeochemistry - a branch of geochemistry that studies geochemical processes occurring in the biosphere with the participation of organisms. It considers the role of organisms in the process of migration, distribution, dispersion and concentration of chemical elements in the earth's crust.

Human impact on the biosphere - a process in which the migration of atoms in the biosphere is sharply accelerated compared to natural biogeochemical processes. The number of elements included in the cycle increases and increases pressure on the inorganic environment: an artificial shell of the Earth is created - noosphere. Knowledge of the patterns of relationships between man and the biosphere, reasonable management of the processes occurring in nature, regulation of man's relationship with nature is the main task of ecology on a global scale. Man is a part of the biosphere, without which he cannot exist.

Circulation of substances - natural cyclic processes of transformation and movement of chemical elements. 98.3% of substances are included in the air cycle, 1.7% in the water cycle. O2, H2, N, C, etc. pass through the gaseous phase, Na, Mg, F, S, Cl pass through the aqueous phase. K and others.

Biological cycle - biogenic migration of atoms, the circulation of substances are two opposite processes - the accumulation of elements in living organisms and mineralization as a result of the decomposition of dead organisms. The formation of living matter prevails on the surface of the land, in the upper layers of the seas, its mineralization - in the soil and the depths of the seas.

Nitrogen cycle - biogeochemical process in the biosphere, in which reducer organisms, as well as nitrifying and nodule bacteria, participate.

Ammonification - decomposition (rotting) of proteins with the formation of ammonia (mineralization of organic matter). It is carried out by reducers.

Nitrification - the process of oxidation of ammonia salts to nitric acid salts (stage I - conversion of ammonia to nitrites, stage II - conversion of nitrites to nitrates). It is carried out by soil nitrifying bacteria (nitrosomonas, nitrosobacter).

Denitrification - decomposition of salts of nitric acid to the formation of gaseous nitrogen. Carried out by soil denitrifying bacteria.

Nitrogen fixation - the formation of nitrogenous compounds by fixing atmospheric nitrogen by free-living soil bacteria (azotobacter) or bacteria living in symbiosis with the roots of leguminous plants (nodule bacteria rhizobium).

Energy transformation - transformation of the energy of solar radiation coming to the Earth into the energy of chemical bonds. Carried out by green plants in the process of photosynthesis. It is spent on the vital processes of all living organisms or is released in the form of heat, or is preserved in the earth's crust in the form of deposits of coal, oil, peat.

Biosphere and man

Biosphere (from the Greek. bios- a life, sphair- film) - the living shell of the Earth. The term is first encountered in the work of the Austrian scientist E. Sues (1831-1914) "The Face of the Earth" (1875). Later, the term "biosphere" was used by other researchers, but the doctrine of the biosphere in the modern sense was formulated by V.I. Vernadsky (1863-1945) in his work Biosphere (1926). According to V.I. Vernadsky, geochemical processes on the Earth and the formation of the face of the Earth are associated with living beings, and the biosphere includes the actual living shell of the Earth (living material in the form of living organisms inhabiting the Earth at any given moment) and former living shells (former material), the boundaries of which determined by the distribution of biogenic sedimentary rocks.

IN AND. Vernadsky subdivided the biosphere into the troposphere, lithosphere and hydrosphere. Troposphere - this is the lower part of the atmosphere up to 20 km high. Migration and exchange of biogenic gases take place in it. Lithosphere - this is the solid surface of the Earth, represented by its upper permeable layers up to 2-5 km deep, below which sedimentary rocks lie, and even lower - remelted rocks of the granite shell. Hydrosphere - This is the water part of the biosphere, represented by rivers, seas and oceans. The depths of the water part reach 10 km or more.

It is believed that since the appearance of life on Earth, living beings have processed the substance of the lithosphere, troposphere and hydrosphere. Therefore, the power of the biosphere is determined by the biomass of organisms living simultaneously on Earth. It is estimated that the biomass of living beings is 2.423x10 12 tons, of which 2.42x10 12 tons fall on the share of terrestrial organisms, 0.003x10 12 tons of water. Oxygen in living matter is 65-70%, hydrogen - 10%, the remaining more than 60 elements - 20-25%.

The biosphere is characterized by a diverse and boundless relationship between its biotic and abiotic parts (living and non-living matter), between plants and animals. Living organisms are interconnected not only by origin, but also by the relationship between them and inanimate nature, i.e. ecologically.

Human life and activity is associated with the lower layers of the troposphere (several meters), the upper layers of the lithosphere (the biogeocenotic cover with soil and subsoil, where the root systems of plants are concentrated) and the hydrosphere.

ECOLOGICAL SYSTEMS

The elementary unit of the biosphere is the ecological system (A. Tensley, 1935), or biogeocenosis(V.N. Sukachev, 1944), which is a combination of living and non-living elements in a certain area. Ecosystems consist of living organisms (biocenoses) and habitat - inert (atmosphere) and bio-inert (soil, reservoir, etc.). They are sometimes separated from one another, but often there are transitions between them.

Being an elementary structural subdivision of the biosphere, the ecosystem is at the same time an elementary unit of biogeochemical activity occurring in the biosphere. Examples of an ecosystem are a lake, a forest area, etc. Biomes should be distinguished from ecosystems, which are understood as communities of organisms confined to certain geographical areas with their climatic and soil zones. The main biomes are forests (coniferous, deciduous, tropical), forest-steppe (savanna), steppe, chaparral, desert, taiga.

The ecological system has an energy input through which the energy of sunlight enters it, and consists of biotic and abiotic parts (Fig. 122). The light energy entering the ecosystem through the input maintains order in this system, preventing the increase in entropy.

The biotic (living) part is represented by producer organisms, consumer organisms and destroyer organisms. Producing organisms are autotrophs - large plants, and in water bodies there are also aquatic multicellular and unicellular floating plants (phytoplankton), living to depths where light still penetrates. Due to the energy coming through the input, producing organisms synthesize organic matter. Organisms-consumers of organic matter are heterotrophs, among which consumers of the I and II order are distinguished. Primary consumers are herbivores, secondary - carnivores that feed on primary

our consumers. Destroyer organisms are bacteria and fungi that decompose the dead protoplasm (organic compounds) of the cells of producer and consumer organisms down to low molecular weight organic and inorganic compounds. Organic compounds are used by the destructive organisms themselves, while inorganic compounds are used by green plants.

Rice. 122.ecological system

The non-living part (abiotic component) of an ecosystem is air, soil, water, oxygen dissolved in water, carbon dioxide, inorganic salts (phosphates and chlorides of sodium, potassium and calcium) and organic compounds, as well as temperature, light, wind and gravity, which have influence on the living part.

All elements of the ecological system make up a single set, and this is determined by the fact that they are interconnected by food chains, which are understood as the transfer of the energy contained in the food of the original source (the sun) from producer organisms through consumer organisms (in a number of food chains, the final link is a person) to destructive organisms. Food chains also maintain the permanence of ecosystems. It is thanks to food chains that ecosystems are stable, which ensures

All ecological homeostasis in nature, and the stability of ecosystems is of a historical nature.

The most important feature of food chains is that their number in each ecosystem is limited, since in each link of each food chain there is a loss of energy during its transfer. As a result, the production of the substance decreases at each link in the chain. For example, 10,000 kg of algae is sufficient for the accumulation of matter in the amount of 1000 kg of aquatic arthropods, and 10 kg of fish mass is sufficient for the accumulation of 1 kg of human matter. Thus, the food chain is represented as a pyramid, consisting of several trophic levels (Fig. 123). At the base are photosynthetic bacteria, which are food for the organisms of the next level, and these organisms serve as food for the next level, and so on.

Rice. 123.biomass pyramid

The chemical mechanisms underlying food chains operate in the form of circulations (cycles) of substances. The carbon cycle (Fig. 124), which is part of all organic compounds, begins with the conversion of carbon dioxide and water into organic matter (food). Part of this substance is used by living organisms during respiration, as a result of which carbon dioxide is returned

is released into the atmosphere, while the other part is stored in the protoplasm. After the death of organisms, their protoplasm decomposes, as a result of which carbon dioxide is also released into the atmosphere. In ecological systems where humans take part, carbon dioxide enters the atmosphere as a result of burning plants as fuel. The oxygen cycle consists in the fact that atmospheric oxygen is used by plants and animals during respiration (burning food), as a result of which energy, water and carbon dioxide are released. Green plants then use water and carbon dioxide in photosynthesis, which releases oxygen, after which the cycle begins again.

Rice. 124.The carbon cycle

More complex is the nitrogen cycle (Fig. 125), the largest reservoir of which is the atmosphere (about 80%). Since most plants and animals cannot use atmospheric nitrogen (N 2), it is converted by soil nitrogen-fixing bacteria, the root system of legumes and blue-green algae into nitrites (NO 2 -) and then into nitrates (NO 3 -). Plants restore nitrates and synthesize proteins. The abundance of nitrogen-containing compounds is characteristic of metabolic products (urine, NH2) of animals and dead materials of organic origin.

Rice. 125. Nitrogen cycle

Nitrogen cycling occurs when soil microorganisms break down animal waste and dead organisms, releasing ammonium, which is converted by nitrifying bacteria into soluble nitrate salts used in plant protein production. As a result of eating plants by herbivores, plant proteins in their bodies turn into animals. In the process of decay

carcasses of plants and animals, denitrifying bacteria convert nitrates into free nitrogen, which goes into the atmosphere, but nitrogen-fixing bacteria convert atmospheric nitrogen into organic compounds available for absorption by plants. Free nitrogen is also converted into nitrates by electrical discharges (lightning). The artificial addition of nitrogen compounds to the soil is associated with the use of chemical fertilizers.

Along with the stability of ecological systems, they are characterized by the so-called ecological succession, which consists in the replacement of some communities in the system by others. The development of ecological systems begins with a primary community, replaced by more advanced communities. Eventually a permanent community is established, which is destroyed only by the impact of strong facts.

INTERACTION OF ORGANISMS IN ECOSYSTEMS

The components of the biological parts of ecosystems are in constant interaction with each other both at the intraspecific and interspecific levels.

Intraspecific interactions are manifested in the competition of organisms for food, light and other vital factors, in the crossing of organisms, care for offspring, social, behavioral and other reactions. On the contrary, interspecies interactions are characterized by the complication of the biological features underlying them, and manifest themselves in the form of competition, antibiosis and various forms of symbiosis (from the Greek. symbiosis- cohabitation).

Interspecific competition, like intraspecific competition, also occurs for food, light, and other factors that are similar for organisms of different species. As for antibiosis (from the Greek. anti- against, bios- life), then it manifests itself in the suppression by organisms of one type of growth and development of organisms of another species. A typical example of this phenomenon is the inhibition of bacterial growth by antibiotic substances produced by other microorganisms. In practice, these substances are called antibiotics.

HUMAN IMPACT ON THE BIOSPHERE

The beginning of human impact on the biosphere dates back to the Neolithic. In the early stages of human history, these impacts were insignificant, but subsequently they began to grow. Drawing attention to this, V.I. Vernadsky called that part of the biosphere, which is especially affected by human activity, the noosphere. A particularly progressive nature of impacts on the biosphere has been noted in recent times, when human activity in the biosphere began to proceed in many directions (Fig. 126).

Rice. 126.Historical world population growth

One of the areas of human activity in the biosphere is the production of energy. It is provided by the extraction and use of energy carriers. In particular, from the middle of the XIX century. began the rapid consumption of coal, and later oil. However, when burning energy carriers, a lot of pollutants are formed, which are widely distributed in the biosphere, crossing the borders of countries and continents. For example, annually as a result of burning liquid and solid fuels only at power plants, thermal power plants and in domestic boiler houses, about 200 million tons of carbon dioxide, 146 million tons of sulfur dioxide, 53 million tons of nitrogen oxides are emitted into the atmosphere. At the same time, the amount of oxygen in the atmosphere decreases, while the proportion of carbon dioxide increases. It is estimated that over the past 100 years, the concentration of carbon dioxide in the atmosphere has increased by 12%. As a result of energy production, a huge amount of ash particles, which contain carcinogenic substances (pyrene, perylene, etc.), also enters the atmosphere. Already by 2000 more than 50% of energy

produced at nuclear power plants. Waste from these power plants also pollute the atmosphere.

The next direction is production of industrial materials, which is accompanied not only by the use of irreplaceable reserves of minerals and water, including drinking water, but also by the formation of various wastes in huge quantities. For example, the mass of annual industrial waste, including chemical compounds, in the United States already in the 60s. 20th century was about 18x10 8 tons. In all industrialized countries, more than 2.5 kg of household, construction, street and other garbage are thrown out daily in terms of one person. Every year in the world, one person throws in an average of several dozen cans and glass bottles, 10 kg of paper.

Every year, in countries with a chemical laboratory base and a chemical industry, about 25,000 new chemical compounds are synthesized, of which only 500 go to the market for use in agriculture, industry, medicine, and other fields.

This gigantic synthesis is accompanied by the release of chemical products into the environment in huge quantities. The production of various materials is also accompanied by dusting of the atmosphere. For example, cement dust contains oxides of calcium and magnesium. The production of aerosols, cleaners and detergents, as well as chemical compounds that give materials water resistance and other properties, has become widespread. Their use leads to environmental pollution.

DDT was synthesized for the first time in 1874, but since 1930 it has been used as a pesticide and drug against malarial mosquitoes. However, already in the 60s. 20th century it was noted that this led to a decrease in the number of birds in Europe, and in the 70s. 20th century it has been found to have a "feminizing" effect on animals. In particular, under the influence of this compound in alligators, the copulatory organ decreases in size, and the effect of metabolites of this compound on men is accompanied by a decrease in the concentration of spermatozoa in their ejaculates, as well as the development of cryptorchidism. A detailed study of the mechanisms of action of DDT and other similar chemical compounds that pollute the environment showed that in the body these compounds and their decay products, being dissimilar in chemical structure

on natural estrogens, yet act as estrogens or androgen blockers. In addition, without causing structural changes in genes, they cause changes in gene expression.

DES (diethylstilbestrol) was synthesized in 1938 and has been used for a long time in animal husbandry to stimulate the growth of cattle, and in medical practice to prevent miscarriages. However, in the 70s. of the last century, it was found that girls born to mothers who took this drug develop vaginal cancer. In addition, DES has estrogenic activity with adverse effects in humans.

In addition to these chemical compounds, there are other synthetic compounds that are dangerous not only because they pollute the environment, but also because of their mechanism of action on humans and animals. Although chemically different from hormones, they nevertheless mimic the signaling actions of natural hormones. As a result, such chemical pollutant compounds are called environmental hormones. Figuratively speaking, the toxicity of some environmental chemical pollutants is the result of a "natural" signal sent by an "unnatural" molecule.

Consideration of the issue of chemical compounds used as food additives deserves special attention, since in recent years many have formed the idea that the use of food additives is one of the conditions for mass production of food.

Food additives are classified into several groups:

1. Dyes. These chemical compounds are used to improve the presentation of meat, vegetables and fruits.

2. Preservatives, antioxidants, stabilizers and emulsifiers. These chemical compounds are used to ensure the preservation of food for a long time under different storage conditions. They process products of both animal and vegetable origin.

3. Enhancers of taste and aroma. These chemical compounds are widely used in the production of both animal and vegetable products.

4. Actiflamings. These additives are chemical compounds that prevent the formation of foam when pouring juices,

as well as caking of sugar, salt, flour and other bulk food products. Although the biological effectiveness of many additives is unknown, nevertheless products with nutritional supplements cannot be considered environmentally friendly.

Finally, chemical synthesis is accompanied by uncontrolled release into the environment of chemical by-products in huge quantities, some of which have mutagenic (carcinogenic) properties. Some chemicals appear to be harmless under normal conditions. However, once in the body, they are hydrolyzed there and turn into mutagens.

The traditional direction of human activity in the biosphere is food production. During the first millennia of its history, man was a predator and herbivore, and the land in the initial period of agriculture could only feed 10 million people. At present, the world produces only enough protein to meet the needs of the population by half. Meanwhile, according to the UN, the population of the Earth in 2000 was 6 billion people, and in another 10 years it will exceed 7 billion. For this reason, it is necessary to have at least twice as much food as now. However, food production also comes with adverse environmental impacts.

One of the traditional directions in food production is the plowing of new lands, logging. Already, arable land covers 1.3 billion hectares (10% of the Earth's surface). However, plowing the soil leads to its erosion. To achieve high yields, they resort to abundant irrigation and chemical fertilizers, of which about 60 billion tons are applied to the soil annually in the world. To protect plants in agriculture, various pesticides, herbicides and defoliants are widely used, which are now produced in the world about 2 million tons annually. These chemicals pollute the environment. Chemicals that enter the human body are also used to preserve and improve the presentation of food products. To this it should be added that human economic activity in nature has always been accompanied by a change in the number of species of animals and plants. For example, in the period from 1600 to 1974, 63 species and 55 subspecies of mammals disappeared from the face of the Earth. The ongoing destruction of animal habitats has endangered an additional 449 species of vertebrates. In private

121 species of mammals, 53 species of birds, 19 species of fish, 47 species of reptiles are threatened by continued overfishing and overfishing.

Such a direction of human activity as transportation of people, industrial and raw materials, also accompanied by dramatic changes in the biosphere. For example, an airliner consumes over 50 tons of oxygen during a flight from Moscow to New York. The transportation of various raw materials is often accompanied by their losses, polluting the ground and water bodies. For example, in recent years, about 0.2% of the transported oil has been dumped into the seas and oceans.

These and other areas of human activity have led to drastic changes in the biosphere, to imbalances in many ecological systems, which has created a new physical, chemical and biological environment for man. The dialectics of human transforming activity lies in the fact that new contradictions have arisen between the biological characteristics of a person and the environmental factors created by him as a result of transforming activity, many of which are dangerous to his health, being mutagens and carcinogens, as well as other pathogenetic factors.

But an even greater threat to humanity arose in connection with the prospect of nuclear war. According to the experts of the World Federation of Scientists, if there are explosions of two nuclear bombs with a capacity of about 5-10 thousand Mt, then only as a result of the shock wave, 750 million people will immediately die, and as a result of the combined action of the shock wave, light radiation and penetrating radiation, there will be about 1.1 billion people have been destroyed and about 1.1 billion more people will be injured and will need medical assistance. Thus, 30-50% of the world's population will be the direct victims of the war.

However, in the event of a nuclear conflict, there may be long-term biological consequences that are no less serious than the immediate ones. Dust and soot formed as a result of the explosion will absorb and scatter sunlight, lower the temperature. Over the Northern Hemisphere, the light intensity can drop to 1% of the norm, and the temperature drops to -40? The dose of radiation on the area constituting 30% of the land will increase to 500 rad. In the next few weeks, in more than half of the northern hemisphere mid-latitudes, radioactive fallout will create an external radiation dose exceeding

100 rad. Radioactive substances will be deposited in the thyroid glands, bones, gastrointestinal tract, and mothers' milk. After the dust settles, the ozone layer is partially destroyed by nitrogen oxide, which is formed during a nuclear explosion. In the Southern Hemisphere, the minimum level of illumination will be 10% of the norm, the temperature of the Earth's surface will reach -18 ° C, and ultraviolet radiation will be tens of percent higher than the norm for several years. Darkening will lead to the cessation of photosynthesis, many plants will die due to lack of light, which will cause disturbances in food chains. A decrease in temperature will have a detrimental effect on the grain harvest, because, for example, in summer, wheat crops die already at -5 ° C, and rice and sorghum do not form seeds at +15 ° C. Corn is very sensitive to temperatures below 10°C.

Since 30% of the land area at mid-latitudes will receive a dose of penetrating radiation of at least 500 rads, then with a fatal dose for humans of 350-500 rads, the death rate will be about 1 billion people in 48 hours. Since the soot and dust will absorb UV radiation, it will damage the immune system, the cornea of ​​the eyes, and cause cataracts in the survivors.

The impact of low temperatures, fires, radiation, strong winds will be accompanied by the decomposition of ecosystems, the reproduction of pests. Animals will die from hunger, frost and lack of water. As a result of the migration of animals, the spread of diseases will begin. Ultimately, the runoff of toxic substances and rain washout of radioactive substances will lead to the death of the animal world. Tropical forests will be especially sensitive, because the plants of the tropics and subtropics do not have a dormant mechanism that allows them to withstand temperatures even above zero.

A clear understanding of the consequences of a nuclear war is a powerful factor in the further activation of anti-war movements.

NATURE AND HABITAT PROTECTION ISSUES

The relationship of society with the environment is one of the most global problems of modern natural science. The concepts of "nature conservation" and "environmental protection" are complex and extensive. Nature protection is a complex of state, public and scientific measures aimed at rational

natural environmental management, restoration and multiplication of natural resources. The protection of the human environment is the protection of everything that surrounds a person, which makes up the ecological system, of which he is a member. The meaning of these events is to find ways to regulate the relationship between human society and nature (living and inanimate).

Protecting nature does not mean keeping it intact, for man will continue to exploit nature, and even more so. We are talking about protection, which will ensure the establishment of a balance between use and restoration, the continuous maintenance of the power of the biosphere. The main tasks of environmental protection measures are not to violate the quantitative and qualitative characteristics of the circulation of substances or energy transformation, i.e. not change the bioproductivity of the biosphere. On the contrary, it is necessary to develop a system of measures aimed at intensifying biological cycles in natural and artificial ecosystems, i.e. to a dramatic increase in the productivity of the Earth. Finally, it is impossible to create habitats for harmful animals, to fill the environment with radiation and chemical pollution.

The political indivisibility of the biosphere necessitates the solution of many problems of nature conservation and the use of its resources, as well as the protection of the human environment, both on a national and international scale.

Being an integral component of the biosphere, man has adapted to his environment, not biologically, but socially with the help of technical and cultural means. However, as a living being, a person is open to the action of environmental pollutants. Maintaining environmental hygiene means maintaining an ecological balance between a person and his environment in order to ensure the well-being of a person, his health. Therefore, in our time, questions have arisen not only of determining the damage already caused to the human gene pool, but also of identifying ways to protect the hereditary material of a person from the facts generated by his activity in the biosphere. The solution of these issues goes in several directions, the main of which are the creation of sensitive test systems for assessing the mutagenic activity of environmental pollutants and in search of approaches to the effective monitoring of genetic processes in human populations.

(development of bases of genetic monitoring of populations). The meaning and necessity of these works lies in the integral analysis of the dynamics of the genetic load, i.e. in the study and evaluation of the frequency of mutations of genes and chromosomes induced by pollutants in relation to mutations historically accumulated in the process of evolution, evolutionarily established systems of balanced genetic polymorphism.

Currently, there are several approaches to register changes in the genetic structure of populations. One of them is related to taking into account population characteristics. As an indicator for assessing the genetic load in humans, medical and statistical indicators are used (frequency of spontaneous abortions, stillbirths, birth weight, survival probability, sex ratio, incidence of congenital and acquired diseases, indicators of growth and development of children). Another approach is related to the consideration of "watchdog" phenotypes, i.e. with the definition of phenotypes that arise due to certain mutations inherited dominantly. In the selected population, the dynamics of the frequency of selected phenotypes among newborns is monitored, for example, the dynamics of the frequency of hip dislocation. Another approach is due to the use of electrophoresis of blood serum proteins and erythrocytes to identify mutant proteins based on their mobility in an electric field. The reason for the change in the charge of a protein molecule may be the replacement or insertion of one or more base pairs in the gene. Finally, the approach associated with the cytogenetic study of spontaneously aborted embryos, stillborns, live births and children with congenital defects is used.

Many countries have national programs for the protection of nature and the environment, which are based on the specifics of local conditions. However, no matter what measures are taken in individual countries, they cannot provide a solution to the whole range of issues related to pollution of the atmosphere, open seas, and the World Ocean. Pollution of the human environment has global consequences, so international cooperation in this area is of great importance. The political indivisibility of the biosphere necessitates international cooperation.

The first major experience of international cooperation in the study of the biosphere is the International Biological Program,

which was established by the International Union of Biological Sciences and operated from 1964 to 1972. About 60 countries took part in the development of the theme “Comprehensive global study of the foundations of biological productivity and the well-being of mankind”. By decision of the UNESCO General Conference, the international intergovernmental program "Man and the Biosphere" was founded, which is a long-term scientific research program in which 80 countries participate. The purpose of the program is to develop the scientific foundations for the rational use and conservation of natural resources, systematic monitoring of changes taking place in the biosphere, developing measures to improve the relationship between man and his environment, predicting the consequences of human economic activity for various ecological systems, promoting education on environmental issues, exchange of scientific information on the issues under study. It consists of a number of projects related to the study of forest ecosystems, the impact of human activity on the resources of rivers, lakes, swamps, deltas, coastal areas.

The program develops research on human ecology, including the study of social and physical adaptation to different conditions, as well as diseases associated with environmental changes. In addition, studies are being conducted to study the genetics of human, animal and plant populations in relation to adverse environmental impacts. Of great importance is the bilateral agreement on environmental protection between Russia and the United States, as well as with other countries.

June 5 - World Environment Day. WHO has adopted the Global Strategy to Improve Health for All. In accordance with this strategy, an indispensable condition for the fulfillment of the tasks set is the preservation and strengthening of peace on Earth. Today we are talking about the preservation of life on Earth.

ISSUES FOR DISCUSSION

1. Formulate a definition of the biosphere and name its subdivisions.

2. What is the elementary unit of the biosphere?

3. What is an ecological system?

4. Explain the relationship between producers, consumers and destroyers in ecosystems.

5. What ensures constancy in maintaining an ecosystem?

6. What is a food chain? How many of these chains are there in ecosystems?

7. Explain the relationship between energy, order and entropy.

8. Talk about the flow of energy through the food chain.

9. What is an ecological pyramid?

10. Explain the meaning of the first and second laws of thermodynamics for the world of living beings.

11. Name the main forms of intraspecific relations of organisms.

12. List the main forms of interspecific relations of organisms, show the medical aspects of these relations.

14. List the main directions of human activity in nature and the adverse consequences of this activity.

Biosphere- the shell of the Earth, the composition, structure and energy of which are determined by the activity of the living matter of the planet, the "film of life", the global ecosystem of the Earth.

The boundaries of the biosphere

This is a huge ecological system in which life found in the lithosphere reaches a depth of 7500 m, and in the atmosphere it is possible at an altitude of up to 25,000 m (troposphere).

The Russian scientist of the last century, academician Vladimir Ivanovich Vernadsky devoted his life to the development of this doctrine. In the book "Biosphere" he showed that living matter, as a single universal factor, involves the inert matter of nature in the cycle, changes the geological shells of the Earth and creates the biosphere. And even later he created a theory about the noosphere, so ahead of his time that only scientists - our contemporaries begin to understand what was discussed - about a spiritualized or, perhaps, informational space enriched with thought, as a geological phenomenon.

Biosphere - the environment of life

The biosphere is like a layer cake, it consists of the following components:

• Lithosphere - the stone firmament of the planet;
• Hydrosphere - the waters of the oceans;
• lower part of the atmosphere.

These geological shells are connected by the circulation of matter and energy flows in the process of biogeocenoses. (Biogeocenosis- elementary structural unit of the biosphere).

There are 4 types of substances:

So, the main force of the planet is living matter, only it is able to transform itself and the world. Accumulating and transforming the energy of the Sun, living matter affects the chemical geological composition of all layers of the biosphere.

Man is a product of the biosphere

Since the appearance of man in the evolution of the biosphere began to act anthropogenic factor(the process of the historical development of man and his influence on the biocenosis).

When did it happen? Science cannot yet accurately answer this question. The more we learn about ourselves, the older we seem. Until recently, it was believed that the age of mankind is no more than 30 thousand years. In recent years, amazing discoveries have been made, artifacts and traces of ancient (antediluvial) civilizations have been discovered, which make us assume that we are hundreds of thousands or even millions of years old.

Historically, most of the reliable information from antiquity has come down to us about life, starting from the time Paleolithic- Ancient Stone Age.

At this stage, the appropriating type of economy prevailed - hunting, gathering ( getting food). The improvement of tools and the growing need for food with a sharp change in climate led to a shortage of food and the disappearance of large herbivores.

In the era Neolithic (new stone age) the process of domestication of animals and crop production is activated. People have learned to use fire. There are more advanced tools and ranged weapons - bow and arrows.

Human influence on the biosphere

The rate of anthropogenic influence is increasing very rapidly. Population growth, a leap in the development of new resource-intensive and not always safe technologies have turned this factor into a defining phenomenon on a planetary scale.

And the biosphere does not have time to adapt to new conditions, hence its instability. Observers and participants in this phenomenon are you and I - now living on the planet.

Mankind intensively consumes all natural resources. By developing cities, improving technologies and improving life inside the major metropolitan areas of the civilized world, man makes the biosphere more and more vulnerable.

We don't have much choice.

• the inevitability of rational nature management;
• ecology of nature and man;
• resource-saving technologies;
• recycling.

These problems can be solved only by relying on a reliable legal framework that allows rational use and protection of nature, ensuring the reproduction of renewable resources and the human environment.

Man has inhabited almost the entire Earth for a long time. Life in different natural conditions has left its mark on the appearance of people, so people from different regions of the Earth differ in appearance.

Distribution of people on Earth

The ancestors of modern humans began to stand out from the community of great apes about 3 million years ago. Scientists believe that primitive people first inhabited the equatorial and tropical latitudes of Africa. This is evidenced by the most ancient fossil remains of humanoids found there. Gradually they moved into Europe. Part of the ancient people penetrated into Australia through numerous islands. During the glacial period, when it was connected to North America, people reached Alaska and then spread throughout the Americas.

The resettlement of a person, like other living organisms, depends on natural conditions, and above all, climate. Most people live between 72° N. sh. and 54°S sh. At the same time, most of them inhabit the plains at a distance of up to 200 kilometers from the shores of the oceans. More than 2/3 of the population is concentrated on only 8% of the land area with favorable natural conditions. In the northern regions of Eurasia and North America, in the northern part of Africa, in the center of Australia and Asia, where the climate is unfavorable due to severe frosts or heat and drought, a small part of the Earth's population lives. The coldest continent has no permanent population at all. Only 1% lives in the highlands (at an altitude above 2000 meters).

human races

The adaptation of individual groups of people to the peculiarities of natural conditions led to a difference in their external appearance. These differences, passed down from generation to generation, are called racial traits. Races - groups of people united by a common origin and the similarity of external signs that have developed under the influence of climate and other features of the natural environment. There are three main human races: equatorial (Negroid), Caucasoid, Mongoloid. There is also a fourth race - which, in a number of ways, is close to the equatorial race.

Representatives of the Caucasian race make up 42% of the world's population, 9% of people belong to the representatives of the equatorial race, and make up 35%. In addition, 14% of the world's population are representatives of mixed and transitional races. Mestizos are descendants born from marriages between Europeans and Indians. Mulattos are descendants of marriages between Europeans and blacks. There are also sambos - descendants from marriages between Indians and blacks or mulattos. Despite external differences, the abilities of people of all races for any activity are the same.

The role of the biosphere in human life

The value of the biosphere and human life, of which he is a part, is great. A person consumes energy for life through food of plant or animal origin. Organisms of the biosphere provide people with oxygen for breathing, as well as clothing, medicines, fuel, building materials, and raw materials for industry. The negative impact of the biosphere is that a person is susceptible to diseases caused by viruses and bacteria.